Summarize Mackinder's Heartland Theory and Spykman's Rimland critique.

• A. The Heartland theory argues that sea power is the sole determinant of global power.
• B. Rimland theory emphasizes controlling the interior ports of Eurasia.
• C. Spykman's Rimland idea has no relation to Eurasia.
• D. Heartland posits power lies in controlling Eurasia's interior; Rimland argues power rests in controlling the rim of Eurasia (coastal and frontier regions) to influence the World Island.

Answer: (D)

These theories explore where genuine geopolitical power resides in Eurasia. Mackinder argued that real power comes from controlling the interior of Eurasia—the Heartland—because this vast, resource-rich landmass is hard to attack and, if dominated, can project influence across the World Island. Spykman pushed back by saying the key is not the heartland itself but the rim around Eurasia—the coastal and frontier regions. Controlling the Rimland gives access to sea routes, critical chokepoints, and alliances that can effectively influence the interior and the wider World Island.

So, the idea that power lies in controlling Eurasia's interior and that Rimland power rests in controlling the coastal and frontier areas to influence the World Island best captures both theories. The other statements misstate the emphasis: sea power alone doesn’t capture Mackinder’s inland advantage, Rimland focus isn’t solely on interior ports, and Rimland does relate to Eurasia by defining the surrounding regions that shape Eurasian power dynamics.